However, it seems Mourinho has his sights set on upgrading the flanks, with Mohamed Salah and Andre Schurrle, linked with a return to the Bundesliga, the likeliest casualties.

Willian, Costa’s former Shakhtar clubmate and fellow Brazil capped star, could also suffer from any new arrivals, as his position on the right appears the most likely place for either Costa or Cuardrado to slot in.

Long linked with a move to the Premier League, highly-rated Costa is expected to be pricey to prise away from Ukraine, after providing 35 goals in 38 assists in 186 appearances, and his potential fee is mooted to be around £30m.

Still only 24, the Brazil wing wizard could be a more potent alternative to industrious Willian, and give the Blues a vital boost in the Premier League title race, after close rivals Manchester City added Wilfried Bony to their attack.

Speaking of the Stamford Bridge side’s interest in him, Costa stated: “It would be a dream to go to Chelsea and is a unique chance for me. I have been at Shakhtar for five years and think it’s time. I will try to negotiate.”

There is speculation though, that the Blues’ sudden interest in tricky Costa is being used as a tactic to pressure Viola into selling Cuadrado.

What does seem certain is that Mourinho wants to shake up his offensive options, and add another weapon to his already impressive armoury as the west London club continue their quest for a quadruple.

The thought of Costa combining with namesake and Stamford Bridge top scorer Diego, plus the likes of Hazard, Oscar and Cesc Fabregas, would give any opposition coach nightmares.

Chelsea, 7/1 to win the Champions League, already have one of the most in-tune forward lines in Europe, but could really challenge Real Madrid’s excellent attacking quartet of Cristiano Ronaldo, Gareth Bale, Karim Benzema and James Rodriguez by bring another Galactico to the Bridge.